This is the 16592nd most frequent Turkish word.
yetkililerinin
"Yetkililerinin" means "of its/their authorities" in English.
Here, "yetkililerinin" refers to the authorities (yetkilileri) of the municipality (belediye).
Belediye yetkililerinin etkinliği iptal etmek zorunda kaldığı öğrenildi.
It was learned that the municipal authorities had to cancel the event.
In this sentence, "yetkililerinin" suggests possession, indicating that the permission belongs to the ministry’s (kültür bakanlığı) authorities.
Festivalin organizasyonunun, kültür bakanlığı yetkililerinin izniyle mümkün olduğu belirtildi.
It was stated that the organization of the festival was possible with the permission of the Ministry of Culture’s authorities.
Here, "yetkililerinin" is used to describe the company's (şirket) governing authorities.